Cord lock device for venetian blinds



'Sept 12, 1944 E. E. scHAEFL-:R 2,357,911

CORD LOCK DEVICE FOR VENETIAN BLINDS Filed June 24, 1945 INVENTOR.

Patented Sept. 172/, 1944 UNITED STATES PATENT OFFICE 2,357,911 CORD LOCK DEVICE FOR VEN ETIAN BLINDS Edward E. Schaefer, Oak Park, Ill. Application June 24, 1943, Serial No. 492,030

6 Claims.

This invention relates to Venetian blinds, and more Yparticularly to an improved cord lock mechanism adapted to secure the raising and lowering cords of the blind in adjusted vertical position and a novel cord arrangement embodying said improved cord lock mechanism. The present invention has particular application to large commercial lblinds which are in use,` for instance, on large bank `and `store windows.

Heretofore, the 'Venetian 4blinds which have been applied to the large, wide windows of banks, stores, etc., have possessed inherent disadvantages arising from their large size which disadvantages have limited their commercial adaptation. 4Because of the relatively great width of such windows, the slats embodied in such blinds were necessarily of relatively great length and because of their thinness the slats were required to be supported by at least three, but for the most part four or more, lifting cords spaced laterally ofthe blind. The cord arrangements and cord lock mechanisms heretofore employed in Asuch large blinds have been found for the most part unsatisfactory and commercially undesirable.

It has been common practice in such large blinds to secure one of the free ends of a single length of cord to the stationary support bar at the top of the blind near one side thereof from which point the cord extended downwardly through slots in the slats to the relatively thick supporting bottom slat wherein it passed around concealed and spaced pulleys and then returned upwardly through the slats to the top support bar. .In the top support bar the cord passed over another pulley adjacent the center of the blind and then extended horizontally through the top of the .blind to a pulley of the cord lock mechanism at one side of the blindv through which it passed downwardly to form a loop. From the loop the cord was returned upwardly through the cord lock mechanism and over the same pulleythereof and then was passed horizontally to a pulley adjacent the center of the blind around which it passed downwardly to the bottom slat. In the bottom slat the cord passed around two spaced pulleys and then returned upwardly to the side of the top support bar opposite from where it started wherein the other free end of the cord was secured.

In such an arragement, the cord was held in two places within the lock mechanism and therefore a two length cord arrangement was eifected. But when one of the sections of such cord was broken due to wear or other causes with the blind in raised position, two of the cord supports on one side orrthe other of the blind were destroyed, with disastrous results. The partially unsupported blind dropped downwardly on one side while being .securely held on the other, causing in many instances the slats to snap and break of their own weight.

Another disadvantage of such an arrangement was that the threading of the single length of cord through the blind caused the blind to work hard and Vthereby increased the strain on the cord, Also, the concealed pulley arrangement in the lower slat necessitated a rather heavy slat and increased the cost thereof.

It is, therefore, an object of my invention to provide an improved cord lock mechanism and a novel lifting cord arrangement employing said cord lock mechanism.

, Another object of my invention is to provide an improved multiple. cord lock mechanism and novel cord` arrangement by which a plurality of cords may be held simultaneously to properly support the blind in vertically adjusted position against collapse in the event of breakage of any one of thecords at any point along its length.

A further object isr to provide an improved cord lock device having a plurality of locking members adapted to simultaneously engage and lock a plurality of lifting cords in adjusted position, said locking members being simultaneously operable by a link mechanism by which the locking of one cord insures the locking of all cords passing through the lock device.

Other and further objects and advantages of my invention will become apparent as this description progresses, reference being had to the accompanying drawing in which,

Figure 1 is a front elevational view of a Venetian .blind structure embodying ymy improved multiple cordv lock device and illustrating the novel lifting cord arrangement;

Fig. 2 is an enlarged front elevational View of my improved multiple cord lock device and a cord loop fastener with part of the cord broken away;

Fig. 3 is a verticalsectionalview taken on the 1 line 3 3 of Fig. 2 looking in the direction of the arrows; Y

Fig. 4 is a vertical sectional View taken on the line 4 4 of Fig. 3 looking in the direction of the arrows; and

Fig. 5 is a horizontalsectional view of the cord loop fastener takeny on the line 5 5 in Fi-g. 3 looking in the direction of the arrows.

The Venetian blind structure shown in Fig. 1 0f `the drawing comprises generally an upper stationary Supporting bar I0, a tilting barV II, aV

' supported at each of its ends for tilting movement by brackets of the tilting mechanism I4 and the cord lock mechanism I5, respectively. The slats are secured to the tilting bar II and extend downwardly on both front and rear sides of the slats I2 and around the Slat-supporting bar I3.

The blind is provided with two lengths of cord I8and I9, each length supporting and serving to raise or lower one-half of Vthe blind. One of the free ends'of the cord lengthY I8 is secured at 2D to the lower Vslat barV I3 VthroughV which Vit extends upwardlyV in alignment withone of the ladder tapes I6 throughthe customary slots (not shown) in the slats' I2 and through the bottom wall of the supporting bar IIl'into a. channelshaped groove 2I which extends longitudinally in the upper surface lof the bar Il) Vto the cord lock Ymechanism I5. VRotatably mounted within the channel-shaped groove 2I of the bar I0 and in Vvertical Valignment withv each of the ladder tapesV I6 are four pulleys 22, 23, 24 andY 25 over whichV the lengths of cord I8 andv I9 are adapted to be passed. Y Y

The 'cord length I8, after passing into the Vgroove 2|, then passes over the'pulley 22 from `which it extends Y longitudinally within the groove 2I to the cord lock mechanism I5. Upon reaching the cord lock mechanism I5, the cord length' I8 passesV over and down around one groove of. a two-groove pulley 26 and .thence downwardly through the right-hand portion or throatV 21 of the lock mechanismv I5. The cord I8 then extends 'downwardly along the righthand end .of the slats I2in a position accessible to the operator wherein it formsa. loop and returns upwardly through the throat 21. 'Ihe cord I8 then passes over and around the other groove orthe'pulley 26 from which it runs longitudinally within the grooveZI of the bar I to the pulley 23. Finally, the cord I 8V passes over and around the pulley 23 Vand downwardly. through the slats I2 and through the slat bar I3 to which its other free end is secured at' 28 in laterally spaced relation with respect to the point of securement 20 ofthe rst free" end of the cord I8.

Thesections of the cord I8 extending between y Vthe points of securement 20 and 28 of the freeends and the Acord lock mechanism I have been designated'on the drawing as I8a and I 8b, Vretudinally with' the grooveV 2I to the cord lock I2 are Ysupported by four laterally spaced ladder tapes I6 of customary form which cord I9 running between the cord lock mechanism I5 and the `points of securement 29 and 30 of the free ends thereof have been designated on the drawing as I 9a and I9b, respectively.

prises a Vhollow casing orsupport member 34 having two vertical Vside walls 35 and 36 and a vertical end wall 38. The casing is open at the top and bottom and is divided intro` two vertical lportions or throats 21 and 32 by a verticalinner wall or web 39 which extends between the inner faces of the vertical side Walls 35 and 36. The casing 34 is also provided with a vdepending ilange bracket 40 and a horizontally'extending ange 40a by which the cord lock mechanism I5 is secured to the support bar I0, the bracket 40 also serving to support one end of the tilting bar II.

The pulley 2s is rotatably supported in'the right-hand throatr21 between the `two Vertical side walls 35 and 36 of` the casing 34 at theex treme upper portion thereof so that the top portion of the pulley 26 extends somewhat above the top'of the casing 34. Similarly, the pulleyV 3l .is rotatably supported in the left-hand throat 32 between the two vertical sidewalls 35V and 36 but in a position somewhat lower than the Y pulley 26, the provision vof differentv pulley heights within the casing serving'to eliminate Vany interference between the two lengths of' VAlso mounted for'V pivotal movement Within' and at the lower portion of the throats or casing sections 21 and 32 are rockable lock mem-rV bers 4I and 42, respective1y, whichare journaled in the casing side walls 35 and 36 bypins 44v'a`n'dv 45, respectively. jThe lock members 4I and 42" are provided with depending tooth ilanges-'46' and 41, respectively, whichV are adapted to engage the two sections of each of the cords I8)v and I9 and hold the same against slippage upf-f wardly through the throats 21 and 32,' thecords la end la being frietieneny held between the Vtooth flanges 46 and 41 and projections 48 and 49 pressed out of the vertical end Wall 38 and,

the central web 39, respectively. When the blindf slats are in lowered position, each of the rock-j' able lock members 4I and 42 assumes Vthe posi-V tion indicated by the brokenV lines in Fig. 4. But with the blinds in any raised position, the

lock members 4I and 42 assume the position in-q dicated by thev full lines of Fig.r4. l.

Each of the lock members 4I and 42 are pro-v-` vided with pins 50 and5I, respectively, the endsl of which extend through curved slots 52 and53j,

' in the vertical casing wall 35 and through'curv'd',

wall of i the support bar I 0' and into the groove Y 2| thereof, over the pulleys 24 and 25, then longimechar'iismISV wherein it extends over a two- Y groove pulley 3I and downwardly throughthe Y other or left-hand throatV 32.` below whichit is loopedinV substantially parallelfrelation to the looped end of thecord I8. The sections of the slots 54 and 55 in theV vertical casing wall 36.1. k The slots 52 and 53 are in alignment with slots'y 5,4 and 55, respectively, andf theyv arecurved. Y upwardlyin an arc defined by thepath of move', .Y ment of the rockable members .4I and 42. outer ends of the pins 50 and 5Ijwhich DIQl .7. trude through the slots 52 to'55, inclusive, and,

extend beyondthe casingY 34, are connectedA by? links 56 and 51. By means of the links 56 and 51, a simultaneous and'unitary rocking movement of the lock members 4I` and 42 is effected with the pins 5I and 52 moving in the curved slots 52, 53, 54 and 55 as the lock members 4| and' 42 turn about their pivots 44 and 45.

After the blind slats have been raised tothe desired level of adjustment, the sections of the cords I8 and I9 which extend below the throats 21 and 32 of the lock mechanism are moved to the left into engagement with the toothed flanges 46 and 41 of the rockable lock members 4| and 42. When this engagement has been effected, the lock members 4| and 42 will rock upwardly from their normal position to their locking position as the cords I8 are released by the operator,

The looped ends of the cords|8 which are held in fixed relative positiony by a fastener 60, may be grasped and manipulated as avunit by the operator. Since the two cords I8 and IS comprise four separate sections 18a, I8b, I9a and I9b, which pass through the cord lock mechanism I5, these same cord sections, upon manipulation of the cord loops as a unit in order to secure the blind in adjusted position as above described, may sometimes fail to properly engage the teeth of either one of rockable members 4I or 42. However, because of the links 56 and 51 which effect simultaneous rocking movement and operation of lock members 4I and 42, such failure of any one of the 1 cord lengths to engage the rockable members 4I and 42 is of no consequence since the proper engagement of only the sections of cord I8, for instance, with the lock member' 4I rocks the lock member 4I into locking position with lengths of cord I8 which, in turn, by means of the links 56 and 51, causes simultaneous rocking movement of the lock member 42 from normal position to frictional locking position in locking engagement with the sections of cord I9. Thus one of the locking members may be pulled into locking engagement by the other in the event it fails to be,- come properly engaged by the cords sought to be locked against slipping. If such simultaneous and unitary action by the lock members 4I and 42 were not present and if the operator failed to initially engage properly the toothed iianges of one of the lock members with one of the cords, the cord not so engaged would be free to slip upwardly through one of the throats to release one of the ends of the blinds, and cause damage thereto. Such inadvertent releaseof one of the sides of the blinds is .entirely prevented by the simultaneous and unitary action of the lock members 4I and 42 by means of the links 56 and 51.

The fastener 60 comprises two oval-shaped frames 6I and 62 which are joined together and maintained in spaced relation by two threaded bolts 63 and 54. Each of the frames 6I and 62 is provided with cross bars 65 and 65, respectively, which divides each of the respective frames into two transverse slots. The two sections of each of the cords I8 and I9 pass through the slots of members 6I and 62, respectively, the four sections of the cords I8 and I9 being held thereby and capable of being operated as a unit.

With a blind of the above described construction embodying my invention, the slats are sup- .ported at four separate points by four lengths of cords I8a, Ib, I9a and I9b. These four lengths of cords are in eiTect four separate supporting cords since they are independent of each other between their points of securement t0 the bottom slat I3 and the points of engagement with the locking members 4I and 42 of the locking mechare respectively caused to engage one or morev ofV anism I5. In the event the left-hand cord length I8a, for instance, shouldl break, no collapse of the heavy blind on. the left-hand end would occur since the blindl would still be supported partially on the left-hand side by the cord I8b which could withstand the increased load until the cord y could be replaced or the blind lowered.

- Although I have illustrated and described one embodiment of my invention in the foregoing drawing and specification it is to be understood that changes and modifications may be resorted to without departing from the spirit and scope of the appended claims. For instance, the cord lock mechanism may be applied to smaller blinds and used with a three cord arrangement with two cords passing down through one throat and one cord passing down through the other throat ofthe lock mechanism, or it may be combined with other cord arrangements.

I claim:

1. In a Venetian blind havingr a plurality of slats and a plurality of lift cords for raising or lowering the slats to adjusted vertical position, a cord lock device comprising a supporting body member, a plurality of rockable cord locking members pivotally supported by said body member and adapted to be rocked from inactive to cord locking position as one or more of said cords said locking members, and a link device operably connecting said cord locking members for simultaneeus and unitary rocking movement from inactive to cord locking position and return, whereby engagement of but one of said locking members with its respective cord and consequent movement of said one locking member to locking position will effect movement oi the other of said locking members to locking position.

2. In a Venetian blind having a plurality of slats and a plurality of lift cords for raising or lowering the slats to adjustedl vertical position, a cord lock device .comprising a supporting body member, a plurality of movable cord locking members movably supported by said body member and adapted to be moved from inactive to cord locking position as one or more of said cords are respectively caused to engage one or more of said locking members, and a link device operably connecting said cord locking members for simultaneous and unitary movement from inactive to cord locking position and return, whereby engagement of but one of said locking members with its respective cord and consequent movement of said one locking member to locking position will effect movement of the other of said locking members to locking position.

3. In a Venetian blind having a plurality of slats and a plurality of lift cords for raising or lowering the slats to adjusted vertical position, a cord lock device comprising a supporting body member, said body member being divided into a plurality of throats through which the plurality of lift cords respectively extend, a pulley in the upper portion of each throat over which the respective lift cords are operatively engaged, said pulleys being arranged in tandem with their axes of rotation in parallel relationship, a plurality of rockable cord locking members, one in each throat, pivotally supported by said body member and adapted to be rocked from inactive to cord locking position as one or more of said cords are respectively caused to engage one or more of said locking members, and a link device operably connecting said rockable cord locking members for simultaneous and unitary rocking movement from inactive to cord locking position and return, whereby engagement of but one of said locking members with its respective cord and consequent movement of` said one locking mem.- ber to locking position will effect movement of the other of said locking members to locking position, t

4. In Va Venetian blind'having a plurality of Vslats' and a plurality of lift cords for raising or Vlowering the slats to adjusted vertical position,

a cord lock device comprising a supporting body member having two side walls and being divided into a plurality'of throats through which the lift cords are passed, a Vplurality of rockable cord locking members, onein each throat, pivotally supported by said side walls and adapted to be rocked `from inactive to cord locking position, at

`least one of said side walls having a plurality of curved slots, oneV adjacent each rockable member, and said slots being curved in the direction of rocking movement of said rockable members,

a pin carried by each rockable cord locking mem ber and extending'through the adjacent curved slot, and a link mounted on and connecting the outer ends of said pins for effecting simultaneous Y and unitary rocking movement of said rockable members from inactive to cord locking position and return. n Y

5. In a Venetian blind having a plurality of slats and a plurality of lift cords for raising or lowering the slats to adjusted position, a cord lock device comprising 'a supporting body member having 'two side walls and at least one partition wall connecting and Vextending between said side walls intermediate their edges anddividing said Vbody member into a plurality of throats through which the Alift cords are passed, a plurality of rockable cord locking members, one in each throat, pivotally supported by and within said side walls and adapted to be rocked from inactive to cord locking position, each of said side walls being provided with' a plurality of curved slots'adjacent the rockable members and the Yslots of one side wallbeing in alignment with the slots on the other side wall, pins mounted Y on each'side of said rockable cord locking'members and extending through the adjacent curved slots in said side walls, and links mounted on and connecting the-outer ends of said pins on the exterior of said side walls for effecting simultaneous and unitary rocking movement of said rockable members from inactive to cord locking position and return. Y

6. A Venetian blind comprising a plurality of slats, a plurality of spaced ladder vtapes for supporting said slats, three or more spaced lift cords adapted to raise or lower the slats tofadjusted position and to support one or more slats whenV in raised position, a cord lock device for adjustably securing each of said cords in radjusted ver` tical position, said lift cords being secured/in spaced relation along and to the lowermost slat and extending upwardly throughVVV said slats to the top of said blind and thence through rsaid cork lock device and said lift cords, after passing through said lock device, being' secured together and adapted to be grasped as a unit by the operator for raising and lowering the slats in hori zontal, parallel position relative to eachother,

and said cord lock device comprising a support- Y ing body member,. a plurality of movable cord locking members pivotaily supported `by said bodytmember and adapted to be moved from inactive to cord locking position to lockV respectively said cords in raised position, and a link device connecting said cord locking members for simultaneous'andunitary movement from inac- Vtive to cord locking position and return, whereby each cord is caused to be engaged and locked by its respective locking member and the blind is properly supported against suddenrelease by at least two spaced cords in the event of breakage of any one of said three or more cords.v Y

I EDWARD E.,SCHAEFER. 

